# CARD_UnlockBackup

## C Specification

      #include <nitro/card.h>

      void CARD_UnlockBackup(u16 lock_id);

## Description

This function frees the access bus to the CARD backup device. If another module is waiting with another ID for the bus to be released, this function will give access permission to that module.

If the specified ID is not currently locking anything, this function will not perform any actions.

This function always succeeds. After the access bus unlocks, it returns control.

## Cautions

All functions that access a CARD backup device must first lock the access bus. Also, a CARD ROM device cannot be accessed at the same time as a backup device. While one bus is locked, lock for the other will be forced to wait.

## Arguments

`lock_id` | ID used for card lock

## Return Values

None.

## See Also

`OS_UnlockCard`, `OS_UnlockCartridge`, `CARD_LockBackup`

## Revision History

09/06/2004 Added prototype description
08/31/2004 Added description of function always succeeding
07/23/2004 Changed lock ID type from u32 to u16
07/13/2004 Addition concerning exclusive control of CARD ROM device and backup device
07/10/2004 Initial version